Note 15 - Commitments and Contingencies (Details Textual) - USD ($) $ in Millions	2 Months Ended	12 Months Ended
	Jul. 31, 2007	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Loans and Leases Receivable, Commitments, Fixed Rates		$ 12.3
Loans and Leases Receivable, Commitments, Weighted Average Rate of Interest		4.65%
Loans and Leases Receivable, Commitments, Variable Rates		$ 310.5
Loans and Leases Receivable, Commitments, Variable Rates, Weighted Average Rate		3.66%
Loan Commitments, Expiration		90 days
Line of Credit, Maturity, Max		1 year 180 days
Operating Leases, Rent Expense		$ 5.8	$ 5.8	$ 3.8
Capital Securities [Member] | Flushing Financial's Capital Trusts [Member]
Proceeds from Issuance of Debt	$ 61.9
Home Equity Line of Credit [Member]
Loans and Leases Receivable, Commitments, Credit		$ 244.6
Line of Credit, Maturity, Max		300 days
Letter of Credit Pledged as Collateral [Member]
Deposit Liabilities, Collateral Issued, Financial Instruments		$ 382.5
Mortgages [Member]
Loans and Leases Receivable, Commitments, Credit		$ 78.1